Swing hammer mill



y 1950 D. w. JACKSON 2,506,455

SWING HAMMER MILL Filed June 2, 1947 2 Sheets-Sheet 1 Fig. I

/Nl/ENTOE," Ei 3 DPYSEIC WALTON JACKSON y 1950 D. w. JACKSON 2,506,455

SWING HAMMER MILL Filed June 2, 1947 2 Sheets-Sheet 2 0 q\ q. N 99 \IT aL 0 l0 m m V N c d N LO ml m //-/\/E/ /To/e; Dsrexc WALTON JACKSON,

' proved grinding mill wherein the housing of Patented M ay z, 1950SWING HAMMER MILL Dcrlo Walton Jackson, Wakefield, England, as-

lignor to The Jeffrey Manufacturing Company, a corporation of OhioApplication June 2, 1347, Serial No. 751,743

Great Britain December 3, 1945 Section 1, Public Law 690, August 3, 1946Patent expires December 3, 1965 7 This invention relates to swing hammermills for pulverizing materials.

An object of my invention is to provide an E- e mill houses a grindingrotor and both the drivin motor for the rotor and the housing of themill are covered and are cooled by air circulated through the enclosureformed by the cover over the motor and grinder housing and over heatexchanging fins on the grinding mill housing by a fan contained withinthe cover.

Other objects of the invention will appear hereinafter, the novelfeatures and combinations bein set forth in the appended claim.

In the accompanying drawings:

Figure l is a half sectional side elevation;

Figure 2 is a section on the line II-II of Figure 1; and

Figure 3 is a perspective view showing a suitable conflguration ofhousing for the mill.

Referring to the drawings, the body part or housing of the mill orgrinder is constituted by (a) an upper portion embodying as an integralcasting a substantially quarter-cylindrical wall I partly bounding thecrushing chamber 33, a. top inlet or feed opening 2 extendingalong suchwall parallel with its axis and midway between the ends of the arc, atangential feed tube 3 extending from such wall and formed in itsintegral closed end 3a with a concentric bore 4 lined with a bush 4acooperating with a bush 5a in the upper integral part is of a segmentalwall part 5 of the housing of the grinder to receive the end journals ofa feed screw 6, and (b) by an open ended tubular base portion 1 adaptedto accommodate a substantially semi-cylindrical screen 8, the upper andbase body portions being bolted and sealed together at the upper openend of the base portion I through opposed flanges Ia and larespectively.

The axis of said tangential feed tube 3 is horizontal and perpendicularto the radius passing through the said inlet or feed opening 2 of thesemi-cylindrical wall I, the cylindrical wall of the interior of thistube being interrupted at the inner end by the said inlet or feedopening 2 which it seals.

The end of the feed screw journaled in the bush 4a carries at itsextremity a sprocket wheel 9 driven via a chain ID from a sprocket wheelII on the shaft l2 of a geared electric motor l3 the base ll of which issecured by depending inverted T-shaped webs or ribs (not shown) to a bedplate l5 forming an integral semi-lateral and diagonal wall or shellpart of the upper part I, such bed plate I! being channeled to receivethe T-shaped bars or ribs. The end of the tangential feed tube 3 remotefrom the inlet or feed opening 2 has a relatively short or shallowupstanding flared and flanged inlet hopper is sealed thereto which, byits upper flange 20, is sealingly but removably fixed about the edges ofa rectangular opening 2| in the top of a part II of a cover thatcooperates with a removable end cover part Hi to form a substantiallyopen bottomed removable separable cover that encloses the mill. Thelower marginal parts of these cover elements are sealed and secured byscrews 40 to the base plate 4! of the'mill which cooperates with theopen bottomed cover to form a complete enclosure for the mill.

The lower open end of the tubular body part I of the mill rests upon andis sealed about a discharge opening in the base plate 4| and is pro-- 2|longed bi-laterally relatively to the upper part to carry housings 22accommodating self-aligning ball bearings 23' for the rotor shaft 24,one end of which passes through and beyond the appropriate housing toreceive a multiple-V 5 rope pulley 25 to enable the shaft to be drivenfrom an electric motor 42 or other suitable power unit, secured to thebase plate 4|. This rotor shaft 24 passes axially across the crushing orreducing chamber 33 which is constituted by a removable nearlysemi-cylindrical screen plate 8 supported by ledges 26 on the lower bodypart of the mill, and two symmetrical segmental, i. e. nearlyquarter-cylindrical, liners 28 seated against the semi-cylindrical wallinner surface vof the upper body part of the mill housing and havingopposed parallel edges 28a spaced apart at the inlet opening of saidwall so as not to obscure such opening.

The said screen plate 8 preferably embodies a single perforated platehaving reinforcing side flanges, its ends being flanged as at 26a forrigidity, its longitudinal flanges having breaker bars 30 interposedbetween them and the lower edges of the two segmental liners 28'. These1 breaker bars are square section bars having the same thickness as thesaid liners and establishing continuity of the screen and the segmentalliners.

Thetwo liners 28 have internal serrated surfaces 31 to cooperate withthe hammers 32 in breaking up the material fed by the feed screw intothe crushing chamber 33 through the inlet opening 2. The hammers 32 areeach in the form of a substantially wedge section bar parallel with theaxis of the crushing chamber and having near body its ends a pair ofrelatively short parallel lateral 3 arms 34 with, apertured bosses 84aat their ends remote from the bar to pivot upon the appropriate one of aplurality of parallel equi-distantly screw to be removed readily whenthe segment 5 has been removed, its appropriate end is fixed to aco-axial extension 4a by a peg 6b and keeper spaced rods secured acrossrotor discs fixed to the rotor shaft, such discs preferably comprisingtwo end annular plates 36 and an intermediate annular plate 31 andconstituting with the hammers, the rotor. A pair of concentricallybossed locating or end plates 38 are fitted to the shaft 24 to securethe said rods against axial displacement.

The purpose of positioning the hopper and feed opening ill at the freeend of the said feed tube 3 is to ofiset such opening relatively to thetop feed opening 2 in the crushing chamber so that the material beingfed in the tube feed 3 and the inlet opening or hopper l9 seals theentrance to the crushing chamber thereby controlling the ingress of airthereto. To enable a regulated supply of air or an inert gas to beadmitted to the crushing chamber without producing a high blast orblower action by the high speed of travelling hammers, one or more,preferably two, inlet ports 39 are provided in the mill body andcommunicating with the crushing chamber via a vertical compartment I40extending across opposed portions of the upper and lower body parts andopen at its lower end to one side of the screen 8, so that air, oraninert gas, can pass through the screen into the crushing chamber.Screw plugs 44 normally close these ports.

Instead of the screen comprising a slotted or perforated plate, it maycomprise a plurality of integral or individually removable bars. -Byusing a detachable screen, variations in screen openings can be effectedreadily.

The cover is formed with a finned ventilating inlet opening 45 coveredby a perforated screen, and one end of the base carries an electricmotor 46 driving a fan 41 rotating in an outlet opening 48 in the base,such opening being covered by a reticulated screen 49. The action ofthis ventilating fan is to circulate and change the cooling air insidethe cover to maintain an even running temperature of the mill and itsmotors 41, I: and 46.

By sealing off the air from the inlet of the mfll, the machine absorbsvery little power to run light as compared to when the machine runsin'open atmosphere.

As seen in Figs. 1 and 2, all of the members which form the body orhousing of the mill or grinder are provided with outwardly extendingheat exchange flanges or fins adapted to transfer. heat to the ambientair within the enclosure formed by the cover parts l1 and I 8 and thebase 4|. The heat exchanging fins of the open ended tubular portion ormember 1 of the mill or grinder areseen at 5|, the fins of the member 5are seen at 52and a fin of the feed tube 3 is seen at 53.

Space, as at 50, is afforded to enable a workman to pass his hand easilyunder the screen when screens are being changed. Also 'by splitting theupper part of the mill body to afford the removable segment 5 thehammers and screens can be changed without completely dismantling themachine. Still further, to enable the feed pin 60.

From the foregoing description it will be apparent that I have providedan improved grinding mill assembly wherein the housing or body of thegrinder or mill is enclosed by a cover or enclosure means having inletand outlet or exhaust openings in which there is a fan for circulatingcooling air over the motors of the apparatus within the enclosure andover the grinder housing in contact with its heat exchange flanges orfins for cooling the motors and grinder.

Obviously those skilled in the art may make various changes in thedetails and arrangement of parts without departing from the spirit andscope of the invention as defined by the claim hereto appended andapplicant wishes therefore not to be restricted to the preciseconstruction herein disclosed.

Having thus described and shown an embodiment of the invention, what itis desired to secure by Letters Patent of the United States is:

A grinder assembly including a base frame, a grinder housing on saidbase frame having external heating exchange fins adapted to transferheat to air flowing therearound, means associated with said grinderhousing forming a material inlet thereto, a rotor in said grinderhousing, a motor for driving said rotor also on said base frame, aseparatable removable two-piece substantially open bottomed cover forsaid grinder housing and motor adapted to be carried and substantiallyclosed at its bottom by said base frame and including an opening adaptedto coowrate with said material inlet, a ventilating inlet in said coverat one side of said motor, a ventilating outlet in said base frame atthe opposite side of said motor, a fan, and means mounting said fan onsaid base frame within said cover and adjacent said ventilating outletfor moving air through said ventilating inlet around said motor andgrinder housing and out of said cover through said ventilating outlet.

DERIC WALTON JACKSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,214,558 Liggett Feb. 6, 19171,381,266 Andrews June 14, 1921 1,560,766 Crites Nov. 10, 1925 1,641,409Bell Sept. 6, 1927 1,660,269 Knox Feb. 21, 1928 1,771,163 Crites July22, 1930 1,829,985 Flaherty Nov. 3, 1931 2,154,963 Swager Apr. 18, 19392,211,518 Scherbaum Aug. 13, 1940 2,279,961 Whittaker Apr. 14, 19422,359,911 Grindle Oct. 10, 1944 2,402,170 Lund June 18, 1946 2,440,051Lind et al Apr. 20, 1948

